<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE article PUBLIC "-//NLM//DTD JATS (Z39.96) Journal Publishing DTD v1.2d1 20170631//EN" "JATS-journalpublishing1.dtd">
<ArticleSet>
  <Article>
    <Journal>
      <PublisherName>ijesm</PublisherName>
      <JournalTitle>International Journal of Engineering, Science and</JournalTitle>
      <PISSN>I</PISSN>
      <EISSN>S</EISSN>
      <Volume-Issue>Volume 6, Issue 4</Volume-Issue>
      <PartNumber/>
      <IssueTopic>Multidisciplinary</IssueTopic>
      <IssueLanguage>English</IssueLanguage>
      <Season>August 2017</Season>
      <SpecialIssue>N</SpecialIssue>
      <SupplementaryIssue>N</SupplementaryIssue>
      <IssueOA>Y</IssueOA>
      <PubDate>
        <Year>2017</Year>
        <Month>08</Month>
        <Day>1</Day>
      </PubDate>
      <ArticleType>Engineering, Science and Mathematics</ArticleType>
      <ArticleTitle>LINEAR AND NONLINEAR ANALYSIS OF THERMAL INSTABILITY IN A POROUS SATURATED BY A NANOFLUID</ArticleTitle>
      <SubTitle/>
      <ArticleLanguage>English</ArticleLanguage>
      <ArticleOA>Y</ArticleOA>
      <FirstPage>71</FirstPage>
      <LastPage>89</LastPage>
      <AuthorList>
        <Author>
          <FirstName>Jada Prathap Kumar</FirstName>
          <LastName>*</LastName>
          <AuthorLanguage>English</AuthorLanguage>
          <Affiliation/>
          <CorrespondingAuthor>N</CorrespondingAuthor>
          <ORCID/>
          <FirstName>Jawali Channabasappa Umavathi** and Channakeshava</FirstName>
          <LastName>Murthy***</LastName>
          <AuthorLanguage>English</AuthorLanguage>
          <Affiliation/>
          <CorrespondingAuthor>Y</CorrespondingAuthor>
          <ORCID/>
        </Author>
      </AuthorList>
      <DOI/>
      <Abstract>In this present article, the onset of convection in a horizontal layer of a porous medium saturated by a nanofluid is investigated analytically using linear and weakly nonlinear analysis. The model used for the nanofluid incorporates the effect of Brownian motion and thermophoresis. The effect of Raleigh-Darcy number, Lewis Number, modified diffusivity ratio, Vadasz number and normalized porosity parameter on the stability of the system is investigated .The analysis reveals that for a typical nanofluid (with large Lewis number) the prime effect of the nanofluids is via buoyancy effect coupled with the conservation of nanoparticles to the thermal energy equation being a second –order effect. Stationary and oscillatory modes of convections have been studied. It is found that the critical thermal Raleigh number can be reduced or increased by a substantial amount, depending on whether the basic nanoparticle distribution is top-heavy, by the presence of the nanoparticles .Oscillatory instability is possible in the case of a bottom-heavy nanoparticle distribution. The linear stability analysis is based on normal mode technique, while for nonlinear theory is based on the truncated representation of Fourier series method. A weakly nonlinear analysis is used to obtain the concentration and thermal Nusselt number. The behavior of the concentration and thermal Nusselt numbers is investigated by a solving the finite amplitude equations. Obtained results have been presented graphically and discussed in details.</Abstract>
      <AbstractLanguage>English</AbstractLanguage>
      <Keywords>Nanofluid, Porous medium, Instability, Natural convection.</Keywords>
      <URLs>
        <Abstract>https://ijesm.co.in/ubijournal-v1copy/journals/abstract.php?article_id=3290&amp;title=LINEAR AND NONLINEAR ANALYSIS OF THERMAL INSTABILITY IN A POROUS SATURATED BY A NANOFLUID</Abstract>
      </URLs>
      <References>
        <ReferencesarticleTitle>References</ReferencesarticleTitle>
        <ReferencesfirstPage>16</ReferencesfirstPage>
        <ReferenceslastPage>19</ReferenceslastPage>
        <References/>
      </References>
    </Journal>
  </Article>
</ArticleSet>